Substrate processing apparatus and method for determining deterioration degree of conductive pipe

Abstract

A substrate processing apparatus includes: a substrate holder; a nozzle that ejects a processing liquid to the substrate; a conductive pipe that supplies the processing liquid to the nozzle; a ground line that connects the conductive pipe to a reference potential; a liquid receiver provided around the substrate holder and receives liquid ejected from the nozzle; and a deterioration degree measuring unit that measures a deterioration degree of conductivity of the conductive pipe. The deterioration degree measuring unit includes: a measurement liquid supply that supplies a measurement liquid to the conductive pipe; a potential difference imparting unit that imparts a potential difference between a liquid contact surface of the liquid receiver and the reference potential; and an ammeter that measures a current value of a current flowing through a charge moving path established via the measurement liquid between the liquid contact surface of the liquid receiver and the ground line.

What is claimed is: 
     
       1. A substrate processing apparatus comprising:
 a substrate holder configured to hold and process a substrate; 
 a nozzle configured to eject a processing liquid to the substrate held by the substrate holder; 
 a conductive pipe connected to the nozzle and configured to supply the processing liquid to the nozzle; 
 a ground line that connects the conductive pipe and a reference potential; 
 a liquid receiver provided around the substrate holder and configured to receive the processing liquid ejected from the nozzle; and 
 a deterioration degree measuring unit configured to measure a deterioration degree of conductivity of the conductive pipe, 
 wherein the deterioration degree measuring unit includes:
 a measurement liquid supply configured to supply a measurement liquid to the conductive pipe and eject the measurement liquid from the nozzle; 
 a potential difference generator configured to impart a potential difference between a liquid contact surface of the liquid receiver and the reference potential; and 
 an ammeter configured to, when the measurement liquid is ejected from the nozzle to the liquid receiver, measure a current value of a current flowing through a charge moving path established via the measurement liquid between the liquid contact surface of the liquid receiver and the ground line. 
 
 
     
     
       2. The substrate processing apparatus according to  claim 1 , wherein the liquid receiver includes a conductive material,
 a resistance meter is configured by a DC power source serving as the potential difference generator and the ammeter, and 
 a first terminal of the resistance meter is electrically connected to the ground line, and a second terminal of the resistance meter is connected to the liquid receiver containing the conductive material. 
 
     
     
       3. The substrate processing apparatus according to  claim 1 , wherein the nozzle includes a tip end portion of the conductive pipe, or includes a member different from the conductive pipe and mounted on the conductive pipe. 
     
     
       4. The substrate processing apparatus according to  claim 1 , wherein the liquid receiver includes a dielectric material,
 the potential difference generator includes:
 an electrode provided close to the liquid receiver; and 
 a voltage source configured to apply voltage to the electrode, 
 
 the ammeter is provided on the ground line, and 
 when the measurement liquid ejected from the nozzle to the liquid receiver passes through the liquid receiver, an induced current flowing through the ground line is measured by the ammeter. 
 
     
     
       5. The substrate processing apparatus according to  claim 4 , wherein a resistor is provided on the ground line. 
     
     
       6. The substrate processing apparatus according to  claim 4 , further comprising:
 an electrometer configured to measure a potential of the electrode. 
 
     
     
       7. The substrate processing apparatus according to  claim 4 , wherein the potential difference generator further includes a switch configured to at least implement a state where the electrode is electrically connected to the voltage source but is not electrically connected to the reference potential, and a state where the electrode is not electrically connected to the voltage source but is electrically connected to the reference potential. 
     
     
       8. The substrate processing apparatus according to  claim 7 , wherein the switch includes:
 a first conductive line that connects the voltage source and the electrode; 
 a first switch provided on the first conductive line; 
 a second conductive line that connects the electrode and the reference potential; and 
 a second switch provided on the second conductive line. 
 
     
     
       9. The substrate processing apparatus according to  claim 8 , wherein the first switch and the second switch are B-contact type switches. 
     
     
       10. The substrate processing apparatus according to  claim 8 , wherein a resistor is provided on the second conductive line. 
     
     
       11. A method for determining a deterioration degree of conductivity of a conductive pipe in a substrate processing apparatus including:
 a substrate holder configured to hold and process a substrate; 
 a nozzle configured to eject a processing liquid to the substrate held by the substrate holder; 
 the conductive pipe connected to the nozzle and configured to supply the processing liquid to the nozzle; 
 a ground line that connects the conductive pipe and a reference potential; and 
 a liquid receiver provided around the substrate holder and configured to receive the processing liquid ejected from the nozzle, 
 the method comprising:
 imparting a potential difference between a liquid contact surface of the liquid receiver and the reference potential; 
 supplying a measurement liquid to the conductive pipe thereby ejecting the measurement liquid from the nozzle to the liquid receiver; and 
 when the measurement liquid is ejected from the nozzle to the liquid receiver, measuring a current value of a current flowing through a charge moving path established via the measurement liquid between the liquid contact surface of the liquid receiver and the ground line.